Soil testing is essential to understand how your soil can impact your yields. The good news is that keeping it simple is often the best strategy. Your soil tests' main focus should be phosphorus, potash, and pH levels.
Of these macronutrients, pH should be paid particularly close attention to. Just like in the human body, an irregular pH level can create diseases that will in turn destroy your yields.
Of course, each type of soil will have its own specific needs. For example, in sandy soil, you will want to increase magnesium levels, while in clay soil, a higher level of calcium or lime should be the focus.
When you receive your samples back, you should aim for about 20 parts per million on a bicarbonate basis for phosphorus, 120-150 parts per million for potash, and a pH level of 6.5-7. If anything is low, you need to address it right away to maximize your yields and prevent diseases.
The source of your soil testing is also crucial. Using an unbiased third party is always recommended over any company that may have a vested interest in the testing results, such as agricultural supply companies.
So, what’s the best way to conduct your soil samples? While many people test every three years, we believe that every 5-7 years should be the standard. The reason for the extended cycle is that three years may not be sufficient to observe measurable changes in soil composition after crop removal, especially if fertilizer applications are not aggressive. Instead, we recommend applying fertilizer aggressively and allowing enough time for the soil to absorb the nutrients before retesting.